A prostaglandin (abbreviated to PG hereinafter) is a derivative of prostanoic acid which has the following formula: ##STR3## and various types of prostaglandins are known.
PG are generally known to possess pharmacological properties, for example they stimulate smooth muscle, have hypotensive, diuretic, bronchodilating, antilipolytic and antinidatory activities, and also inhibit blood platelet aggregation, gastric acid secretion and gastro-intestinal ulcers, and are, accordingly useful in the prevention and treatment of hypertension, peripheral circulatory failure, asthma, gastro-intestinal ulcers, thrombosis and myocardial infarction, in the induction of labour and abortion in pregnant female mammals and in the improvement of fertility, the control of oestrus, the contraception and the menstrual regulation in female mammals, and as diuretic agents.